An accurate knowledge of the phase equilibria boundary of pure components and/or mixtures is not only a matter of fundamental scientific interest. It is very important for test of proposed equations of state, (EOS), pair potentials, mixing rules, etc. It is also of great practical importance for geochemistry, for power generation and for many chemical engineering processes.
There are two recent reviews on techniques and methods on high pressure PVT data and phase equilibria measurements by Schneider and Deiters Fluid Phase Equilibria 29 145-160 (1986) and by Marsh et al. Fluid Phase Equilibria 29 161 (1986).
The well-known PT vapor-liquid coexistence line of pure water was used to test the behavior of the phase detector and to establish the best experimental procedure to follow. The performance of thsi new detection method was then assessed with measurements of bubble points for pure water and for sodium chloride solutions.
Many other kinds of phase separations can also be detected and measured in accordance with this invention.